A 44-residue hybrid peptide (CB (1-24)-Arg-Ser-Tyr-Tan (4-21)) incorporating 1-24 residues of cecropin B (CB) and 4-21 residues of thanatin (Tan) was designed and constructed. The CB-Tan gene was cloned into expressio...A 44-residue hybrid peptide (CB (1-24)-Arg-Ser-Tyr-Tan (4-21)) incorporating 1-24 residues of cecropin B (CB) and 4-21 residues of thanatin (Tan) was designed and constructed. The CB-Tan gene was cloned into expression plasmid pGEX-3X and expressed in E.coli BL21. The fusion protein was purified by affinity chromatography. After digested with enterokinase the gene product released with antibacterial activity and gave one band in Tricine-SDS-PAGE.展开更多
本试验旨在研究天蚕素A-马盖宁杂合肽对小鼠小肠黏膜结构、黏膜免疫功能和肠道菌群的影响。选取18只健康且体重相近的BALB/c小鼠随机分成3组:对照组(生理盐水0.75 m L/d灌胃)、低剂量杂合肽组(0.26 mg/m L的杂合肽0.75 m L/d灌胃)、高...本试验旨在研究天蚕素A-马盖宁杂合肽对小鼠小肠黏膜结构、黏膜免疫功能和肠道菌群的影响。选取18只健康且体重相近的BALB/c小鼠随机分成3组:对照组(生理盐水0.75 m L/d灌胃)、低剂量杂合肽组(0.26 mg/m L的杂合肽0.75 m L/d灌胃)、高剂量杂合肽组(0.52 mg/m L的杂合肽0.75 m L/d灌胃)。试验期为6周。结果表明:1)2个杂合肽组十二指肠绒毛长度均显著大于对照组(P<0.05),各段小肠的隐窝深度均显著低于对照组(P<0.05),各段小肠绒毛长度/隐窝深度均显著高于对照组(P<0.05)。2)与对照组相比,2个杂合肽组各段小肠黏膜内免疫球蛋白A阳性表达水平均显著升高(P<0.05)。3)2个杂合肽组小肠黏膜内白细胞介素(IL)-2、干扰素-γ(IFN-γ)及IL-4含量均显著高于对照组(P<0.05),而IFN-γ/IL-4各组之间差异不显著(P>0.05)。4)2个杂合肽组盲肠内容物中的大肠杆菌数量均显著低于对照组(P<0.05),双歧杆菌与乳酸杆菌数量均显著高于对照组(P<0.05)。由此得出,天蚕素A-马盖宁杂合肽灌胃能改善机体小肠黏膜结构;可促进免疫球蛋白A的表达来提高小肠黏膜免疫防御功能;可促进IL-2及IFN-γ的分泌来提高肠道细胞免疫水平,促进IL-4的分泌以提高肠道体液免疫水平并能够保持辅助性T细胞(Th)1/Th2的平衡状态;可有效降低肠道致病菌大肠杆菌的数量并显著增加肠道益生菌双歧杆菌和乳酸杆菌的数量。展开更多
A hybrid peptide gene was designed and synthesized. Its encoding peptide is constructed from residues 3～14 of magainin and residues 1～13 of melittin. The MA E gene was cloned into plasmids pUC18 and pBV220. By DNA s...A hybrid peptide gene was designed and synthesized. Its encoding peptide is constructed from residues 3～14 of magainin and residues 1～13 of melittin. The MA E gene was cloned into plasmids pUC18 and pBV220. By DNA sequencing, the whole sequences of this gene is confirmed to be correct. The recombinant plasmid pBMA\|E was expressed in \%E.coli\% DH5α. A gene product band can be seen with Tricine\|SDS\|PAGE. The MA E hybrid peptide was purified by immobilized metal affinity chromatography. Bioactivity assay was carried out in liquid turbidity method. The bactericide value to \%E.coli\% K 12 D 31 is 0.182.展开更多
文摘A 44-residue hybrid peptide (CB (1-24)-Arg-Ser-Tyr-Tan (4-21)) incorporating 1-24 residues of cecropin B (CB) and 4-21 residues of thanatin (Tan) was designed and constructed. The CB-Tan gene was cloned into expression plasmid pGEX-3X and expressed in E.coli BL21. The fusion protein was purified by affinity chromatography. After digested with enterokinase the gene product released with antibacterial activity and gave one band in Tricine-SDS-PAGE.
文摘本试验旨在研究天蚕素A-马盖宁杂合肽对小鼠小肠黏膜结构、黏膜免疫功能和肠道菌群的影响。选取18只健康且体重相近的BALB/c小鼠随机分成3组:对照组(生理盐水0.75 m L/d灌胃)、低剂量杂合肽组(0.26 mg/m L的杂合肽0.75 m L/d灌胃)、高剂量杂合肽组(0.52 mg/m L的杂合肽0.75 m L/d灌胃)。试验期为6周。结果表明:1)2个杂合肽组十二指肠绒毛长度均显著大于对照组(P<0.05),各段小肠的隐窝深度均显著低于对照组(P<0.05),各段小肠绒毛长度/隐窝深度均显著高于对照组(P<0.05)。2)与对照组相比,2个杂合肽组各段小肠黏膜内免疫球蛋白A阳性表达水平均显著升高(P<0.05)。3)2个杂合肽组小肠黏膜内白细胞介素(IL)-2、干扰素-γ(IFN-γ)及IL-4含量均显著高于对照组(P<0.05),而IFN-γ/IL-4各组之间差异不显著(P>0.05)。4)2个杂合肽组盲肠内容物中的大肠杆菌数量均显著低于对照组(P<0.05),双歧杆菌与乳酸杆菌数量均显著高于对照组(P<0.05)。由此得出,天蚕素A-马盖宁杂合肽灌胃能改善机体小肠黏膜结构;可促进免疫球蛋白A的表达来提高小肠黏膜免疫防御功能;可促进IL-2及IFN-γ的分泌来提高肠道细胞免疫水平,促进IL-4的分泌以提高肠道体液免疫水平并能够保持辅助性T细胞(Th)1/Th2的平衡状态;可有效降低肠道致病菌大肠杆菌的数量并显著增加肠道益生菌双歧杆菌和乳酸杆菌的数量。
文摘A hybrid peptide gene was designed and synthesized. Its encoding peptide is constructed from residues 3～14 of magainin and residues 1～13 of melittin. The MA E gene was cloned into plasmids pUC18 and pBV220. By DNA sequencing, the whole sequences of this gene is confirmed to be correct. The recombinant plasmid pBMA\|E was expressed in \%E.coli\% DH5α. A gene product band can be seen with Tricine\|SDS\|PAGE. The MA E hybrid peptide was purified by immobilized metal affinity chromatography. Bioactivity assay was carried out in liquid turbidity method. The bactericide value to \%E.coli\% K 12 D 31 is 0.182.
